Pumping mechanism



May27, 1941- D. J. DESCHAMPS 2,243,374

PUMPING MECHANI SM Filed July 31, 1940 INYENTOR. Des/re J Desc/mm s Patented May 27, 1941 PUMPING MECHANISM Desire .1. Deschamps, Rutherford, N. 1., assl nor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application July 31, 1940, Serial No. 348,924

9 Claims.

in relationship to the weight of air used by the engine in a unit oftime, so as to keep the air/fuel ratio of the mixture within certain limits, as previously determined to be most desirable.

An object of this invention is to provide a constant pressure pump of variable output, in which the output can be varied at will without interfering with the continuous operation thereof, or of the engine supplied thereby.

Another object of the invention is to provide, in a pump of the character indicated, unitary means for varying both the quantity impulse of the pump's output,.as well as the duration of each injection and the timing as measured by the rotation of the crankshaft, and in a predetermined relationship which will assure maintenance of most eflicient combustion conditions throughout the whole speed and power range of the engine.

These and other objects of the invention will become apparent from inspection of the following specification when read with reference to the accompanying drawing wherein is illustrated the preferred embodiment of the invention. It is to be expressly understood, however, that the draw'. ing is for the purpose of illustration only, and is not designed as a definition of the limits of the invention, referencebeing had to the appended claims for this purpose.

In the drawing,

Fig. 1 is a longitudinal sectional view of a device embodying the invention Fig. 2 is a transverse sectional view along the line 22 of Fig. 1;

Fig. 3 is a fragmentary longitudinal sectional view of the device of Figs. 1 and 2, as viewed at a right angle to the viewpoint of Fig. 1; and

Figs. 4 and 5 show possible variations in the contour of one element of the device.

The pump shown includes two sections 5 and 6, held in abutting relationship by screws 8, and a third section 1 abutting the section 6 and held thereto by screws 9. A hollow drive shaft II has a splined member l2 keyed thereto, and a flange l4 on said hollow shaft II is formed into a spur gear to mesh with, and drive, a similar spur gear l6 with a hub [1 that is rotatably received in a bearing sleeve I8 carried by the housing section 5; additional bearing sleeves 2| and 22 being provided to facilitate rotation of the hollow drive shaft II. The gears l4 and I6 constitute the pumping elements and receive the fuel by way of inlet passage 23 and port 24, the latter registering with the pump chamber at the region of tangency of the two pitch circles of the gears as does also the outlet port '21 which discharges the pumped fuel to the chamber 28, from which the fuel emerges by way of outlet passage 29. In the event of excessive pressure development a second path of fuel discharge is automatically made operative by the yielding of the spring 3! which normally holds valve 32 against its seat and thus normally blocks emergence of fuel by way of relief passage 33, leading back to the fuel source (by connections not shown).

Now will be described the novel means for controlling the quantity and timing of the fuel discharge from passage 29. As shown, said means is. embodied in a sleeve 38 and a hollow rotary valve 31, the former being secured fixedly in the extending portion of the housing section 1, and the latter being rotatable and slidable within the former. A single port 38 in the cylinder 36 registers with the pump discharge passage 29, as indicated in Fig. 3. and also registers with the circumferential recess 39 in the cylinder.

31; the said recess 39 being of sufllcient extent, longitudinally, to maintain such condition of registry with port 38 throughout the range of longitudinal movement of said cylinder 31. One

or more ports 4| extend through the wall of cylinder 31 and thereby serve to direct the pumped fuel into the hollow interior of said cylinder 31, from which it subsequently emerges in successive pulsations, the duration of each pulsation (and hence the quantity of fuel delivered to the engine cylinders) being variable by operation of the manual control shown at 43. In the illustrated embodiment the control 43 is in. the,

formof a bifurcated lever, or yoke, having end pins adapted to ride in the circumferential recess 44 of a. collar 46 secured to the outer race of a ball bearing assembly 41 whose innerrace is secured about the reduced section 48 of the cylinder 31 and abuts the shoulder 49 of the latter, wherefore manual shifting of the yoke 43 about the axis of its supporting shaft 5| (journaled in the housing section 1) will produce a proportional longitudinal movement of the cylinder 31 within the stationary sleeve 36. The cylinder 31 is continuously rotated in synchronism with pump shaft II by reason of thekeyed connection between the square inner surface (see Fig. 2) of the hollow shaft H, and the corresponding square end 54 of the cylinder 31.

The means by which the longitudinal relationship between sleeve 35 and valve 31 controls the pumps output further includes a number (preferably equal to the number of combustion chambers to be supplied with fuel) of ports 51 through the wall of sleeve 35 in exact traverse alignment and evenly spaced on the circumference of sleeve 35; the port 56 in valve 31 registering in rotation with each of the ports 51 and the outlets 58 to which are connected the pipes (not shown) leading to the fuel injection nozzles, installed on the intake manifold ahead of the engine cylinder intake port, or installed directly in the cylinder heads of the engine. It will be apparent that the longitudinal shifting of the valve 31 will produce a variation in the size of the arc of registry between the opposite edges of opening 56, on the one hand, and the opposite edges of fixed port 51 on the other. Thus is provided a control of the length of time, during each cycle of rotation, when flow'of fuel can take place by way of said intermittently registering openings.

To lubricate the surface of cylinder 31 which has rotating relationship to sleeve 36, I provide two or more circular grooves along the inner Surface of cylinder 35, to receive lubricant from a chamber formed by a longitudinally extending recess 62 in the outer surface of cylinder 35, from which the lubricant reaches the grooves Si by way of radial passages 63. Port 54 is preferably connected permanently to the pressure lubricating system of the engine.

The position of valve 31 shown in Fig. l corresponds to the no output" adjustment, as the point of port 56 is in position to move past port 51 in sleeve 35 without allowing any fuel to flow therethrough.

With the shape of port 56 as shown, when the valve 31 is moved outwardly, while the injection becomes longer, it starts sooner and ends later with respect to the position of the crankshaft. Other shapes could be used for port 56 in order to'provide a difierent method of timing the iniection. Figs. 4 and 5 show two such other shapes. The shape of Fig. 4 would provide fixed rate of -discharge through said passages, said to interrupt the delivery of fluid to said discharge passage at regular intervals in each cycle of rotation of said drive shaft, and means for regulating the duration of each such interruption.

2. In a pump, a drive shaft, a pair of concentric cylinders in alignment with said drive shaft, means responsive to rotation of said drive shaft to deliver fluid to the interior of the inner cylinder, means including a passage through the outer cylinder for discharging said fluid from said inner cylinder, means for controlling the rate of discharge through said passages, said means comprising surfaces on said inner cylinder to interrupt the delivery of fluid to said discharge passage at regular intervals in each cycle of rotation of said drive shaft, means for regulating the duration of each such interruption, said last named means comprising a member engageable with said inner cylinder to cause axial movement thereof in relation to said outer cylinder, when said member is shifted from one predetermined position to another, and means for shifting said member.

3. In a pump, a drive shaft, a valve mechanism comprising a pair of cylinders one ofwhich is rotatable within and slidable longitudinally of the other, means for drivably connecting said rotatable cylinder with said drive shaft, means comprising registerable passages in said cylinders for causing flow of fluid from the pump during a portion of each revolution of the drive shaft, and

timing of the begining of the injection and the timing of the ending of the injection would vary with the length of the injection. With the port shaped as in Fig. 5, one would obtain the opposite result, namely, variable timing for the beginning and fixed timing for the ending of the injection.

Port need not necessarily be cut through the wall of distributing valve 31 as shown in Figs. 2 and 3, but could be milled out to form a depression whose outer rim would have the same shape and outline, and would communicate with the bore of the distributing valve. by means of a drilled hole in the widest part of the port.

What is claimed is:

1. In a pump, a drive shaft, a pair of concen tric cylinders in alignment with said drive shaft,

means responsive to rotation of said drive shaft to deliver fluid to the interior of the inner cylinder, means including a passage through the outer cylinder for discharging said fluid from said inner cylinder, means for controlling the means for changing the degree of registry between said openings, to vary the amount of fluid discharge of the pump, said means being operable during the continued operation of the pump.

4. In a pump, a drive shaft, a valve mechanism comprising a pair of cylinders one of which is rotatable within and slidable longitudinally of the other, means for drivably connecting said rotatable cylinder with said drive shaft, means .comprising registerable passages in said cylin ders for causing flow of fluid from the pump during a portion of each revolution of the drive shaft, means for changing the degree of registry between said openings, to vary the amount of fluid discharge of the pump, said means being operable during the continued operation of the pump, said last named means comprising a thrust member surrounding said shiftable cylinder, and means for changing the position of said thrust member.

5. In a pump, adrive shaft, a pair of concentric cylinders in alignment with said drive shaft,

means for drivably connecting one of said cylinders with said drive shaft to cause relative rotation between said cylinders, means comprising registerable openings in said cylinders for producing periodic discharge of fluid from the pump during operation thereof, and means for maintaining a continuous fllm of lubricating 011 between the relatively moving cylinders.

6. In a pump, a drive shaft, a pair of concentric cylinders in alignment with said drive shaft, means for drivably connecting one of said cylinders with said drive shaft to cause relative taining a continuous fllm of lubricating oil between the relatively moving cylinders, said last named means comprising a groove extending longitudinally along the outer surface of the outer cylinder, and meansfor maintaining communication between said groove and the engaging surfaces of both cylinders.

7. In a pump, a drive shaft, a pair of inter-\ engaging pumping elements, one of which is integral with said drive shaft, inlet and discharge passages converging adjacent the area of inter-.

engagement of said pumping elements, and means for regulating the amount of flow through said discharge passage, said means comprising a pair of concentric cylinders, registerable openings through which the fluid flows from said tegral with said drive shaft, inlet and discharge passages converging adjacent the area of interengagement of said pumping elements, means for regulating the amount of flow through said discharge passage, said means comprising a pair of concentric cylinders, registerable openings through which the fluid flows from said discharge passages to the interior of the inner ylinder, and additional registerable openings through which the fluid within the inner cylinder is delivered therefrom while the drive shaft is rotating through a predetermined portion of its arc of revolution, and means operable during continued rotation of the drive shaft to vary the duration of each delivery interval.

9. In a pump, a drive shaft, a pair of interengaging pumping elements, one of which is integral with said drive shaft, inlet and discharge passages converging adjacent the area of interengagement of said pumping elements, means for regulating the amount of flow through said discharge passage, said means comprising a pair of concentric cylinders, registerable openings through which the fluid flows from said discharge passages to the interior of the inner cylinder, and additional registerable openings through which the fluid within the inner cylinder is delivered therefrom while the drive shaft is rotating through a predetermined portion of its arc of revolution, and means operable during continued rotation of the drive shaft to vary the duration of each delivery interval, said last named means comprising a member operable to vary the degree of registry between said last named registerable openings.

DESIRE J. ,DESCHAMPS. 

